Machine-gun



A. T- DAWSON AND G. T. BUCKHAM.

MACHINE GUN.

A P P L I C A T I 0 N F l L E D l U N E l9, QIB- 1 ,327,086, Patented Jan. 6, 1920.

M H m snrrnn srarns PATENT orricn.

ARTHUR TREVOR DAVI' SON AND GEORGE THOMAS BUCKHAM, OF WESTMINSTER, LONDON, ENGLAND, ASSIGNORS TO VICKEBS LIMITED, OF WESTMINSTER,

ENGLAND.

MACHINE-GUN.

Application filed June 19, 1918.

To all whom it may concern:

Be it known that we, Sir ARTHUR TREVOR DAWSON, knight, and Sir GEORGE THOMAS BUCKHAM, knight, both subjects of the King of Great Britain, residing at Vickers House, Broadway, l/Vestminster, in the county of London, England, have invented certain new and useful Improvements Relating to Machine-Guns, of which the following is a specification.

It is found that with machine guns carried by aircraft especially when the latter are traveling at high altitudes and at high speeds, the lowering of the temperature of the parts of the gun, owing to the circulation of the cold air through the gun, has a detrimental effect on the working of a gun by reason of the lubricating oillosing its natural viscosity and the working parts consequently moving in a sluggish manner and even at times becoming jammed. A similar effect is sometimes experienced with machine guns other than those carried by aircraft, when subjected to a freezing temperature for any length of time.

According to the invention we provide means, preferably comprising a low voltage electric heater, for increasing the temperature of the working parts of the machine gun when the latter is out of action. The said electric heater, which may be placed in the mechanism casing of the gun, serves by radiation of heat to raise the temperature of the contiguous parts of the gun. Means may be provided whereby the circuit of the electric current for the heater is automati cally broken when the gun ommences to fire and is automatically closed when the gun ceases to fire, the said means advantageously comprising a switch controlled by the trigger or firing lever.

' In order that the said invention may be clearly understood and readily carried into effect we will describe the same more fully with reference to the accompanying drawing, in which 7 Figure 1 is a sectional side elevation of the rear part of the mechanism casing of a Vickers automatic gun showing the electric heater in position and also showing the aforesaid switch controlled by the trigger or firing lever.

Fig. 2 is a plan of the said electric heater, and

Specification of Letters Patent.

Patented Jan. 6, 1920.

Serial No. 240,782.

Fig. 3 is a diagrammatic representation of the circuits of the electric heater.

A is the mechanism casing, A the trigger or firing lever, B the switch member controlled by the trigger and B the stationary switch member with which the switch member B is adapted to engage. O is the electric heater which in the example shown is composed of two flat coils (see Fig. 2) contained in a copper casing C (see Fig. 1), this casing being disposed at the bottom of the rear part of the mechanism casing and being held in position by a metal strip C engaging with the stud A D is the low voltage supply cable for the heater. This cable is connected to any suitable source of supply of electric energy, indicated diagrammatically at E in Fig. 3.

The trigger A has a downward extension at to which is attached in any suitable manner an insulating block 72* riveted to the switch member B. The other or stationary switch member B has spring fingers between which the forward part of the switch member B engages as shown by Fig. 1, the latter member having an insulating piece 6 serving to guide this member into position. The switch member B is electrically connected to a stud b which is insulated from the mechanism casing. It will be seen that when the trigger is in the position shown by Fig. 1 (in which event, the gun is not working) the switch members B, B are in engagement with one another and the heater C is therefore in operation. When the trigger is pressed to fire the gun, the switch member B is moved out of engagement with the switch member B and the circuit through the' heater is thereby broken.

Instead of the switch being controlled by the trigger as above stated, it might be operated separately, the switch being closed when the gun is temporarily out of action and opened when the gun is to be fired.

What we claim and desire to secure by Letters Patent of the United States is 1. The combination with a machine gun, of a heater forming a permanent attachment of the gun for raising the temperature of the working parts when the gun is out of action.

2. The combination with a machine gun, of an electric heater mounted within the mechanism casing of the gun for raising the temperature of the working parts when the gun is out of action.

3. In a machine gun, the combination of an electric heater forming a permanent attachment of the gun for raising the temperature of the working parts of the gun and a switch arranged in the circuit of said heater for closing said circuit when the gun is out of action and breaking it when the gun is in action.

&. In a machine gun, the combination of an electric heater for raising the temperature of the working parts of the gun and a switch arranged in the circuit of said heater and connected to the trigger of the gun so that said circuit is automatically closed when the gun is out of action and is automatically broken when the gun is in action.

5. In an automatic gun, the combination with the mechanism casing and the trigger of said gun, of an electric heater disposed in said casing, a switch arranged in the circuit of said heater and composed of two members one of which is connected to the trigger and the other to the casing so that when the trigger is in the firing position said switch members will be out of electrical connection with each other and when the trigger is not in the firing position said switch members will be in electrical connection with each other.

In testimony whereof we aflix our signatures.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUCKHAM. 

